Steady-state and dynamic models of solid oxide fuel cells based on Satin Bowerbird Optimizer

2018 ◽  
Vol 43 (31) ◽  
pp. 14751-14761 ◽  
Author(s):  
E.A. El-Hay ◽  
M.A. El-Hameed ◽  
A.A. El-Fergany
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Solid Oxide Fuel Cells ◽  
Dynamic Models ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Satin Bowerbird

scholarly journals Steady State Analysis of Direct Thermal Energy Storage in Solid Oxide Fuel Cells (SOFC)

2017 ◽  
Author(s):  
Francesca L. Moloney ◽  
Nor Farida Harun ◽  
David Tucker
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Mass Flow ◽  
Thermal Stresses ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Air Mass ◽  
Fuel Cell Performance

This study explored the potential for TES in solid oxide fuel cells (SOFCs) by investigating the steady state fuel cell performance with a one-dimensional numerical model. The effect of including TES was simulated by increasing and decreasing the mass of the interconnect, stainless steel 441, as the storage medium. Using a model previously developed and tested in MATLAB Simulink®, the interconnect mass was varied from 42% to 99% of the total SOFC mass under the same initial and inlet conditions. The SOFC fuel studied was syngas derived from coal. As the size of the TES increased for constant cathode air mass flow, the heat capacity increased, resistance to heat conduction decreased and the temperature profile through the fuel cell became more uniform. As temperature gradients decreased, thermal stresses and the chance of cell failure reduced. Larger interconnect masses resulted in higher cell voltage and thus yielded higher efficiencies. The cathode air mass flow was also adjusted to control two different temperature conditions: constant average temperature and constant solid temperature difference across the cell. Instead of minimizing the size of the interconnect to reduce the cost of the SOFC, the interconnect material can be increased to add sensible heat storage directly to the fuel cell, increase heat and electrical conduction, and improve the efficiency of the fuel cell for hybrid systems as well as stand-alone fuel cells.

Operation and Performance Limitations for Solid Oxide Fuel Cells and Gas Turbines in a Hybrid System

2004 ◽  
Author(s):  
Miriam Kemm ◽  
Andre Hildebrandt ◽  
Mohsen Assadi
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Solid Oxide Fuel Cells ◽  
Hybrid System ◽  
Gas Turbines ◽  
Solid Oxide ◽  
Temperature Gradients ◽  
Oxide Fuel ◽  
Single Operation ◽  
Operational Window

Temperature limitations of Solid Oxide Fuel Cells (SOFC) in transient single operation and steady-state Hybrid System (HS) operation with Gas Turbines (GT) are presented. For transient SOFC simulations, an unsteady-state SOFC model was developed by upgrading a detailed validated steady-state model. As critical SOFC single operation modes, concerning the risk of material cracking due to exceeding SOFC transient temperature gradients, heat-up and cool-down are investigated. For minimization of transient SOFC temperature gradients at start-up and shut-down, a stepwise heat-up and cool-down procedure is proposed. Concerning HS off-design and part-load operation, the impact of SOFC temperature limitations on the operational window is investigated. Results show a reduced operational window due to exceeding local SOFC temperature gradients, which can be reduced by optimal adaptation of GT to SOFC size.

Estimation of Spatial Temperature Distribution in Co-Flow Planar Solid Oxide Fuel Cells

2007 ◽  
Author(s):  
Handa Xi ◽  
Jing Sun ◽  
Jian Chen
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Temperature Distribution ◽  
Solid Oxide Fuel Cells ◽  
Design Guidelines ◽  
Solid Oxide ◽  
Maximum Temperature ◽  
Oxide Fuel ◽  
Detailed Model ◽  
Transient Operations

Significant temperature distribution has been identified in planar Solid Oxide Fuel Cells (SOFCs) during both steady state and transient operations. In order to ensure the material stability and device protection, the maximum temperature and temperature gradient have to be closely monitored and securely maintained below certain limits. In practical implementation, however, direct measurement of the temperature distribution inside the SOFC is difficult and costly. In this paper, an observer is designed and the corresponding performance is analyzed for estimating the temperature distribution in the co-flow planar SOFC. To facilitate the observer design, we introduce a reduced-order nonlinear SOFC model that is obtained based on the high-order detailed model derived in our previous work. Using three easily accessible measurements, namely the stack voltage and the temperatures of the solid structure at the entrance and exit of the SOFC, the observer designed based on the low order model can effectively estimate the temperature profile during both steady-state and transient operations. Model-based analysis and simulation results are presented to demonstrate the performance of the estimation scheme and to provide design guidelines.

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